Vincent Ho doesn’t work for, consult for, own shares in, or get money from any company or organization that would benefit from this article. They have also said they don’t have any other relevant affiliations besides their academic job.
Health officials say that two people in Victoria and New South Wales died after eating smoked salmon that was tainted with listeria. Both were over 70 and had underlying health conditions.
Australia’s top doctor hasn’t said for sure that these three cases are caused by smoked salmon, but he says it is “likely” the case.
So what is listeriosis, who’s at risk and what can we do to prevent getting sick?
Listeriosis is caused by eating food contaminated with a bacterium called Listeria monocytogenes. It’s not very common, but if it leads to septicaemia (blood poisoning) or meningitis (inflammation of the membranes around the brain), it can be fatal.
Listeriosis is more likely to spread to older people, pregnant women and their babies, and people whose immune systems aren’t strong enough.
Melon, raw milk, soft cheeses, salads, raw vegetables that haven’t been washed, cold diced chicken, pre-cut fruit, and fruit salad have all been linked to outbreaks in the past.
Smoked salmon is a popular delicacy enjoyed around the world. When properly stored and consumed fresh, it makes for a tasty and nutritious meal or snack. However smoked salmon also carries certain food safety risks if it has spoiled or gone bad. So what exactly happens if you eat smoked salmon that is past its prime? Let’s take a closer look.
How Can You Tell if Smoked Salmon is Bad?
Before we talk about what happens when you eat bad smoked salmon, it’s important to know how to spot it. Here are some telltale signs that your smoked salmon has gone off:
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Slimy texture – Fresh smoked salmon should feel smooth and firm If it has become excessively sticky, slippery, or mushy, it has likely spoiled
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Mold growth—fuzzy mold may appear on the surface of smoked salmon that has gone bad. Discard immediately if this is observed.
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Bad smell: smoked salmon that is past its best has a smell that is like rotten fish, ammonia, or something else.
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Discoloration – The flesh should be glistening and reddish orange. Gray, brown, or yellow hues indicate spoilage.
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Expired date – Check packaging for the sell-by or use-by date and don’t consume smoked salmon past this timeframe.
Being able to identify these signs of spoiled salmon will help you avoid accidentally consuming bad fish. Trust your senses – if something seems off about the look, smell, or texture, it’s better to be safe than sorry and throw it out.
Foodborne Illness is the Primary Risk
So what happens if you eat smoked salmon that has clearly turned bad? The most common consequence is food poisoning, caused by dangerous bacteria growth. Smoked fish is particularly susceptible to a bacteria called Listeria monocytogenes. Listeria can multiply even when refrigerated.
Eating food contaminated with Listeria bacteria can lead to an illness called listeriosis. Most healthy adults may only experience temporary, flu-like symptoms from a Listeria infection. However, it poses a greater health risk to young children, pregnant women, seniors, and those with compromised immune systems.
In severe cases of listeriosis caused by tainted seafood, symptoms may include high fever, severe headache, stiff neck, nausea, abdominal pain, diarrhea, confusion, and convulsions. Listeria can sometimes be fatal, especially in high risk groups.
So consuming spoiled, bacterially-contaminated smoked salmon puts you at risk of food poisoning and its related nasty symptoms.
Other Potential Health Effects
Along with foodborne pathogens like Listeria, deteriorated smoked salmon may also contain increased histamine levels and harmful toxins. Histamine is what causes the unwanted inflammatory response we associate with food allergies. High levels of histamine from consuming spoiled fish can potentially trigger symptoms even if you’re not actually allergic.
Additionally, chemical changes from proteins and fats breaking down as smoked salmon goes bad can produce toxic compounds like hydrogen sulfide and putrescine. Ingesting these toxins found in spoiled fish can irritate the digestive system and make you sick.
What to Do if You’ve Eaten Bad Smoked Salmon
If you ate some smoked salmon and then realized afterwards it was likely spoiled, don’t panic. Here’s what you should do:
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Look out for any symptoms of food poisoning like nausea, vomiting, abdominal cramps, etc over the next 12-48 hours.
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Drink plenty of fluids to prevent dehydration if vomiting or diarrhea occurs.
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Take an antihistamine if your mouth or throat feels itchy or irritated after eating the spoiled salmon.
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Monitor your temperature and see a doctor if you develop a fever along with flu-like symptoms.
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Call your doctor right away if symptoms are severe, especially if you are in an at-risk group for foodborne illness complications.
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Dispose of any remaining smoked salmon from that package so others don’t accidentally eat it.
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Report the incident to the store or manufacturer who sold the spoiled salmon.
With prompt treatment for dehydration and other symptoms, most otherwise healthy adults will recover on their own within a few days. But seek medical care immediately if symptoms worsen or become dangerous.
How to Avoid Eating Spoiled Smoked Salmon
Now that you know the risks of consuming bad smoked salmon, here are some tips to avoid it happening in the first place:
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Check sell-by and use-by dates and don’t purchase or eat expired smoked salmon.
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Inspect packaging carefully for leaks, tears, or signs of damage. Avoid if compromised.
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Refrigerate smoked salmon right away, at 40°F or below. Keep refrigerated until ready to eat.
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Discard any smoked salmon with an unpleasant odor, slimy texture, or abnormal color.
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Consume refrigerated smoked salmon within 3-5 days of opening the package. Freeze for longer storage.
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When thawing frozen salmon, keep it in the fridge until fully thawed before eating.
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Avoid letting smoked salmon sit out too long at room temperature before refrigerating.
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Purchase smoked salmon from reputable suppliers with high food safety standards.
Following basic food safety practices will lower your chances of ending up with spoiled fish. But if you do inadvertently eat bad smoked salmon, see a doctor promptly if any concerning symptoms arise. With quick action, you can recover from a foodborne illness and avoid severe complications.
Frequently Asked Questions
How long after eating bad smoked salmon do symptoms appear?
Symptoms of foodborne illness from spoiled smoked salmon usually begin within 12-48 hours after ingesting. However, they can take up to a week to develop in some cases. Monitor yourself carefully in the hours and days following consumption of questionable salmon.
Can you tell if smoked salmon is bad by the smell?
Yes, smell is one of the most reliable ways to identify spoiled smoked salmon. Fresh salmon has a mild, pleasant aroma, while spoiled salmon smells unpleasant, fishy, or ammonia-like. Never eat smoked salmon with an offensive odor.
What happens if you eat moldy smoked salmon?
Moldy smoked salmon may contain mycotoxins that can cause illness. Symptoms may include vomiting, nausea, and diarrhea. Certain molds like Aspergillus flavus can even produce carcinogenic compounds. So it’s very risky eating moldy smoked fish.
Does cooking spoiled smoked salmon make it safe?
No, cooking does not make spoiled smoked salmon safe for consumption. Bacteria like Listeria and Salmonella, along with toxins, can still persist after cooking. Always discard spoiled smoked salmon rather than trying to cook or heat it.
Can expired vacuum-sealed smoked salmon still be eaten?
No, you should not eat expired smoked salmon, even if it is still vacuum-sealed. Anaerobic bacteria like Clostridium botulinum, which causes botulism, can grow even in tightly sealed packages. Err on the side of caution and throw out smoked salmon past its use-by date.
Conclusion
To wrap up, smoked salmon that has spoiled presents health hazards like Listeria, histamine toxicity, and harmful chemical compounds. Consuming rancid smoked fish can cause symptoms ranging from temporary food poisoning to life-threatening complications. Use caution when handling smoked salmon, look for signs of spoilage, and discard any that seems unfit to eat. With proper storage and handling, you can continue to safely enjoy smoked salmon and minimize the risks from foodborne pathogens.
How does it spread?
Listeria is found widely in soil, water and vegetation, and can be carried by pets and wild animals. Listeria can get into food in restaurants and home kitchens because the bacteria can be found and spread in places where food is handled.
Contamination levels of raw fish, including salmon, tend to be low. Contamination can occur at any point along the food production chain. It can occur at the food processing stage, for instance in machines used in salting, skinning and slicing fish.
Listeria has also been found in smoked fish products. It is not possible to produce cold-smoked fish that is consistently free from listeria. This is because cold smoking does not involve cooking the fish by heat during the smoking process in order to produce the characteristic delicate texture. In contrast, hot smoking, which is carried out a higher temperature but leaves a less moist and firm texture, kills off listeria.
Manufacturers of cold-smoked fish try to ensure levels of listeria are low. They do this by obtaining product from producers that have a history of non-contaminated fish, freezing, restricting shelf-life time or by using preservatives.
But Listeria monocytogenes is quite a hardy bacterium. It can survive at refrigerated temperatures; viable listeria has been found in vacuum-packed smoked salmon at 4°C.
Listeria also has mechanisms to survive acidic environments such as the stomach, and to grow in oxygen-free environments. Temperatures of 74°C or greater are needed to kill it.
What are the symptoms?
Eating foods that contain listeria won’t necessarily make you sick. It can survive in the body, moving between cells (human phagocytes) for a long time. This is, in part, why there can be a long “incubation period” between ingestion and onset of illness. This can be as long as 70 days but is usually around three weeks.
Symptoms include fever, muscle aches and gastrointestinal problems such as nausea, vomiting and diarrhoea.
In severe cases, symptoms can include collapse and shock, particularly if there is septicaemia. If the infection has spread to the central nervous system, more worrying symptoms will occur, such as headache, stiff neck, confusion, seizures and the person may go into a coma. In such cases, the fatality rate is as high as 30%.
In pregnant women, the bacteria are thought to cross the lining of maternal blood vessels and then enter the fetal circulation of the placenta. Infection during pregnancy can lead to miscarriage, stillbirth and newborn infections.
Treatment for confirmed infections involves antibiotics and supportive measures such as intravenous fluids for dehydration.
If an infection does happen during pregnancy, antibiotics should be given right away to keep the baby or fetus from getting sick.
But even with very prompt treatment, infections can be deadly in high-risk groups.